Knitting of tubular fabric



Nov. 1, 1966 c. w. PERKINS KNITTING OF TUBULAR FABRIC 4 Sheets-Sheet 1 Filed Oct. 29, 1963 INYENTOR CHARLES wmm PERKINS BH 1% HTTo RN LYS Nov. 1, 1966 c. w. PERKINS 3,282,070

KNITTING 0F TUBULAR FABRIC Filed Oct. 29, 1963 4 Sheets-Sheet 2 lNVENT'OI-Z CHARLES WILL/N {Rm/5 MW ATToRNL-Ys Nov. 1, 1966 c. w. PERKINS 3,282,070

KNITTING 0F TUBULAR FABRIC Filed Oct. 29, 1963 4 Sheets-Sheet 5 INVENTOR CH A R LES WILLIN PER KINS 5f M /M HT'TORNEYS INVENTOR ATTORNEYS 4 Sheets-Sheet 4 CHARLES WILLIN PERKINS C W PERKINS KNITTING OF TUBULAR FABRIC Nov. 1, 1966 Filed Oct. 29, 1963 United States Patent KNITTING 0F TUBULAR FABRIC Charles Willin Perkins, Leicester, England, assignor to Hosiery Equipment Limited, Leicester, England Filed Oct. 29, 1963, Ser. No. 319,815 Claims priority, application Great Britain, Oct. 29, 1962,

40,830/62; Apr. 25, 1963, 16,317/63 14 Claims. (Cl. 66-147) This invention is for improvements in or relating to the knitting of tubular fabric and has for an object to facilitate the treatment of a succession of articles produced in tubular form by circular knitting.

In the production of some circularly knitted articles, for example half hose, it is a common procedure to knit a succession of the articles joined end to end in continuous tubular form without pressing off the product from the needles, successive articles being joined to the preceding ones by courses formed of a joining thread sometimes known as a draw thread which are subsequently removed in separating the articles from one another. The separation is commonly effected by hand and in one procedure the joining thread is formed of a soluble yarn and the articles are separated individually by severing the draw thread, remaining parts of which are subsequently dissolved out when the articles are subjected to dyeing and finishing treatment. The invention seeks to avoid the need for the laborious and time consuming procedure of separating the articles by hand.

In accordance with the invention there is provided a method of producing tubular knitted articles on a circular knitting machine according to which the articles are knitted in succession and connected to one another by a joining thread which is weaker than the yarn used for forming the articles and the articles are afterwards separated from one another by a mechanical pull applied at appropriate intervals .to rupture the joining thread. It is found in practice that the soluble yarn previously used as aforesaid as the joining thread is suitable for use in practising the invention as it will readily rupture on having a sudden pull applied to it.

In practising the invention the mechanical pull is arranged to be applied to the tubular string of knitted articles as the knitted fabric is leaving the machine below the take down rollers. It may be applied by means of pulling rollers into the nip between which the fabric is arranged to be engaged. Preferably the fabric on production is segregated from the pulling means except when a separating operation is required whereupon it is caused to engage the pulling means to effect the rupture of the draw thread. The fabric may be moved bodily into engagement with the pulling means to effect rupture of the joining thread.

By the method as just described half hose or similar articles which are normally produced end to end in a continuous string can be separated singly by mechanical means as they .are produced without interfering with the normal operation of the knitting machine, so that the end to end connection of the articles is utilised to provide a suflicient length to engage the take down rollers by -which the take down tension is applied, the separation of the articles taking place at a later stage.

The invention further provides apparatus for use with a circular knitting machine for separating articles produced in succession in continuous tubular form comprising means for gripping and pulling the tubular knitted fabric after it has passed the take down rollers and means for clamping the tubular material above the lowest joining thread whereby a sudden pull is applied to rupture the joining thread. Conveniently the clamping means is positioned immediately above the take down rollers but it may if desired be placed below them. It is so positioned "ice that for various sizes of articles to be produced on the machine one joint will occur between the position of the clamping means and the position of the pulling means.

The pulling means may comprise two driven rollers serving to grip the knitted fabric between them when required and exert the downward pull thereon for pulling the lowermost article from the remainder of the fabric. There may be guiding means presenting an aperture through which the tubular fabric is caused to pass, such guiding means being mounted so as to be movable to deflect the fabric into engagement with the pulling means, and means may be provided for moving said guiding means to deflect the fabric when a parting operation is required.

The pulling means and the clamping means may be actuated by a common operating device which may be operated by a control device on the machine, for example a projection on a control chain, so as to be brought into operation at an appropriate stage during each complete cycle of operations.

The clamping means may comprise opposed clamping bars between which in their open setting the fabric is arranged to pass, two spaced rack bars respectively carrying the clamping bars to project transversely therefrom into the space between the rack bars, and a rack wheel engaging simultaneously with both rack bars at opposite parts of the wheel so as to move the rack bars in opposite directions and thereby move the clamping bars into and out of their closed position.

The apparatus may be provided as an attachment for fitting to an existing knitting machine and adapted to be mounted thereon below the needle cylinder.

Means may be provided whereby operation of the pulling means will be automatically arrestedin the event of a pull being exerted on the tubular fabric in excess of a Y predetermined amount.

The foregoing and other provisions of the invention will now be described in relation to a convenient form of construction which is illustrated by way of example in the accompanying drawings in which:

FIGURE 1 is a perspective view of the lower part of a circular knitting machine having the present apparatus fitted thereto,

FIGURE 2 is a cross-sectional plan view taken through the upper part of a box-like casing forming part of the present apparatus and shows parts of the apparatus on a scale larger than that of FIGURE 1,

FIGURE 3 is a plan view showing details of the clamping means,

FIGURE 4 is a detailed side elevation view of other parts of the apparatus,

FIGURE 5 is a diagram showing the circuit of a pneumatic system, and

FIGURE 6 is a circuit diagram of electrical connections in the apparatus.

In FIG. 1 there is shown part of a circular knitting machine of a known kind used for knitting mens seamless socks or three quarter hose, as sold under the Registered Trademark Komet. Reference will be made only to the parts of the machine needing mention for an understanding of the present invention. The machine comprises a main frame 10 above which there is mounted a control drum 11 and a mounting for a control chain 12 which is racked around at regular intervals and operates in known manner to control the racking of the control drum 11 when required to effect changes in the cycle. of knitting operations, a complete cycle being performed during one circuit of movement of the control chain 12. On the frame 10 there is an upper frame 13 on which the control drum 11, a needle cylinder, operating parts therefor and feeder and feeder control means, none of which are shown, are mounted. On the front of the lower frame 10 there are two forwardly projecting brackets one of which is shown at 14 which support a ring 15 on which there is rotatably supported a bracket assembly 16 carrying the usual take down rollers 17 positioned below the rotatable needle cylinder. A length a tubular knitted fabric extending downwards from the needle cylinder is indicated at 18 and it passes between the take down rollers 17 which apply the required knitting tension. The bracket assembly 16 and take down rollers 17 are caused to rotate in known manner in step with the needle cylinder during the performance of rotary knitting. When knitting is performed by reciprocation at appropriate times for the formation of heel and toe pockets in the tubular hosiery blank 18, the rotation of the bracket assembly 16 and take down rollers 17 is arrested.

The control chain 12 is shown as being mounted on a driven sprocket wheel 19 at the upper end of its path and extending downwardly to be guided around a lower sprocket wheel 20 mounted on a spindle carried by a bracket attached to the frame 10 being part of the normal machine. At an intermediate part the control chain 12 engages with a small sprocket 21 on a spindle 22 carried by a bracket 23 mounted on the frame 10. The spindle 22 and sprocket 21 form the normal winding apparatus for adjustment of the chain 12 to reset it and for this purpose there is a crank handle 24 provided on the spindle 22 and capable of being coupled thereto by means of a notch 25 engaging with a projection 26 on the spindle for manual winding, see FIG. 4.

The apparatus provided in accordance with the invention is mounted on the machine at the front thereof and its main parts are mounted in a box-like casing 27 carrying an upstanding hollow pillar 28 supporting an extension part 29 at its upper end, this assembly being clamped to the bottom frame 10 at each side thereof, for example by means of clamping plates such as that indicated at 30 provided at suitable points. Depending from the bottom of the casing 27 there is a delivery funnel 31 and associ ated air pipes 32 and 33. The apparatus comprises pulling means as aforementioned which are contained in the casing 27 and driven by an electric motor 34 attached to the exterior thereof and clamping means which are contained in the extension part 29.

Referring more particularly to FIG. 1 and 2, the pulling means comprises a pair of rollers 35 and 36 which are mounted on horizontal spindles 37 and 38 at the same level and in direct peripheral contact with one another, these rollers preferably having solid metallic cores sheathed with yieldable sleeves, for example rubber or similar sleeves, for engagement with the tubular knitted fabric. The roller 35 is fixed to spindle 37 which in turn is driven from the motor 34 by pulleys 39 and 40 and a V-belt 41 which is contained in a protecting casing 42, FIG. 1. The roller 35 drives the roller 36 by peripheral contact therewith so that the rollers rotate together oppositely. Associated with the pulling means there is a guiding meansconstituted by a movable funnel 43, the lower part of which indicated at 43a in FIG. 2 is carried by an arm 44 fixed to a pivot spindle 45 to which is attached an operating arm 46.

It will be noted that in the setting shown in FIG. 2, the bottom 43a of the funnel lies to one side of the pulling rollers 35, 36 with its center, as seen from above, in line with the nip between the rollers. By clockwise turning movement of the operating lever 46 arm 44 will be swung to the left as seen in FIG. 2 and bring the bottom 43a of the funnel immediately over the nip between the rollers 35 and 36. The lower part of the funnel passes through the top wall of casing 27 through an elongated opening therein permitting the to and fro movement of the funnel. The funnel is fitted with a cover plate 47 which slides over a machined part 48 of the casing 27 to cover the elongated opening in the top of casing 27.

During the operation of the knitting machine between the times when it is required to separate the last knitted garment, e.g. a sock, from the remainder of the fabric 18 the funnel 43 is maintained in the position shown in FIGS. 1 and 2 to guide the tubular fabric as it is produced to pass down to one side of the pulling rollers 35, 36. The funnel 43 is retained in such a position by means of a two armed latch 49 pivoted at 50 and acted on by a plate spring 51. This latch 49 has a shoulder 52 which co-operates with a pin 53 on the operating lever 46 to retain the parts in the position of FIG. 2. When the tubular fabric depending from the bottom 43a of the funnel 43 is required to be engaged with the pulling rollers 35, 36 it is necessary for the latch 49 to be released from the pin 53 whereupon a spring (not shown) acting on the spindle 45 will turn the spindle to rock the levers 44 and 46 in a clockwise direction, as seen in FIG. 2, into engagement with a suitable stop (not shown).

To operate the latch 49 for release of operating lever 46 there is provided a double acting pneumatic piston and cylinder device comprising a cylinder 54 having a piston rod 55, the cylinder being pivoted at 56 to a supporting lug or bracket 57 on the casing 27. The piston rod 55 is coupled at 58 to an L-shaped lever 59 keyed to a squared part 60 of an upstanding spindle extending through the pillar 28 and indicated at 61 in FIG. 3. The extremity of lever 59 carries a pin 62 arranged to ride on one edge of operating lever 46 and on the inner edges of the two arms of the latch 49, the junction between which arms is curved internally to permit smooth passage of the pin 62 from one arm to the other. When a parting operation is required to take place the pneumatic cylinder 54 is operated to cause its piston to move outwardly so that piston rod 55 moves in the direction towards the top of FIG. 2. This rocks the L-shaped lever 59 anti-clockwise about its supporting spindle and near the end of the stroke of the pneumatic piston the pin .62 will engage the left hand arm of latch 49 and rock the latch clockwise so as to release its shoulder 52 from pin 53. The spring acting on spindle 45 will then swing the bottom of the funnel 43a over the pulling rollers 35, 36.

The clamping means for gripping the tubular knitted fabric at a position above the take down rollers 17 is also operated by the pneumatic cylinder 54 when the latter is energized to rock the L-shaped lever 59 anticlockwise. Such movement causes the spindle 61 to be turned anti-clockwise as seen in FIG. 3. On the upper end of spindle 61 there is fixed a rack wheel 63 opposite parts of which engage at the same time with rack teeth 64a, 65a formed on two parallel spaced rack bars 64 and 65 slidably mounted in the extension part 29 aforementioned. The rack bars 64 and 65 carry respectively parallel clamping bars, the clamping bar 67 being strengthened by a buttress piece 68. Normally the clamping bars 66 and 67 are separated as shown in FIG. 3 and the tube of knitted fabric 18 passes through the space between them on its way to the take down rollers 17. When a parting operation is to be performed, energisation of the air cylinder 54 causes its piston rod 55 to be moved outwardly, i.e. towards the top of FIG. 2, and this causes the spindle 61 to be rotated anti-clockwise as seen in FIG. 3. The turning of the spindle immediately operates the rack bars 64 and 65 in the directions to bring the clamping bars 66 and 67 together to grip the tubular knitted fabric 18 between them. Matters are so arranged that the clamping of the fabric between the clamping bars 66 and 67 occurs immediately before the funnel 43 moves across to bring the knitted fabric depending from it into engagement with the pulling rollers 35 and 36. That is to say the clamping bars 66 and 67 grip the fabric above the take down rollers immediately before or at the same time as the latch 49 is tripped by the pin 62. To ensure that the clamping bars 66 and 67 will grip the fabric firmly, they may be provided with an interfitting rib 66a and groove 67a respectively.

Control of the air cylinder 54 is derived from an air valve 69 FIG. 4 mounted on a carrier plate 70 and having an operating stem 71 which co-operates with a cam lever 72 pivoted at 73 to the carrier plate 70. The cam lever 72 is urged by a spring (not shown) acting on valve stem 71 against a stop 74 also on the plate 70. The plate 70 is pivoted on a mounting screw 75 to a fixed bracket 76 but is maintained normally in the vertical attitude shown in FIG. 4. The cam lever 72 co-operates with a feeler block 77 on a feeler arm 78 pivoted at 79 to the fixed bracket 76. The feeler arm 73 is arranged alongside the chain 12 at a position where it passes over part of the periphery of chain wheel 21. At an appropriate position on the chain 12 there is a lateral projection 80 for cooperation with the feeler 7'7. When this passes into engagement with the feeler 77, the arm 78 is rocked to the left as seen in FIG. 4 and the feeler 77 is caused to have a camming action on cam lever 72 to rock the latter anticlockwise and cause depression of valve stem 71. This has the effect of operating the clamping bars 66 and 67 to grip the tubular fabric 18 immediately above the take down rollers 17, and causing the-bottom part of the fabric depending from the bottom 43a of the funnel 43 to be moved into engagement with the pulling rollers 35 and 36 so that a sharp pull is applied to the bottom article, e.g. a sock, on the fabric tube, causing it to be separated from the remainder of fabric by rupture of a joining thread which is weaker than the main yarn. The severed article is then passed downwardly by the pulling rollers 35 and 36 and projected into the discharge funnel 31, FIG. 1.

As soon as the article is discharged into the delivery funnel 31 it is caused to be delivered therefrom through the tubes 32 and 33 by a current of air which is forced through tubes 32 and 33 from an air pipe 81, FIG. 1, which projects into an end cap 82 below and to one side of the funnel 31. From the tube 33 the article may be,

delivered into a receiving container or into a trunking system wherein articles are carried away by air flow to some central point related to a group of machines.

When, after a brief period of time, the chain projection 80 has passed the follower 77 the latter is released and the spring on valve stem 71 causes reverse operation of the valve 69 and this gives rise to reverse energisation of cylinder 54. When this occurs spindle 61 with its squared lower end 60 turns in the clockwise direction as seen in FIGS. 2 and 3 thereby releasing the clamping bars 66 and 67 from engagement with the fabric and rocking the L- shaped lever 59 in a clockwise direction as seen in FIG. 2. During this rocking motion of lever 59 the pin 62 first of all rides along the inner edge of the right hand arm of latch 49 and then engages with the operating lever 46 urging it in an anti-clockwise direction against the action of the spring on spindle 45 until the pin 53 rides past the shoulder 52 whereupon the latch 49 gravitates into latching engagement with the pin 53 and the parts are reset. As a safety measure to prevent damage to the fabric or needles of the knitting machine the carrier plate 70,

FIG. 4 is coupled by a link 83 to a stop and start lever 84 of the knitting machine which is pivoted at 85 to a flange of the bracket 23. The lever 84 may be a belt shipper lever which moves a driving belt between fast and loose pulleys and has a lug 36 which is coupled to the link 83 by a yieldable connection provided by a spring 87 and end stops 88 and 89. The lever 84 is one which is moved to the right as seen in FIG. 4 to disconnect the drive to the knitting machine whenever the latter is stopped by the operator or by an automatic stop motion. When lever 84 is so moved the link 83 is caused to rock the carrier plate 70 through being connected at 90 to the upper end of the plate, causing the plate 70 to be rocked on its pivot 75 in the direction to withdraw the cam lever 72 and air valve 69 away from the follower 77 so that any actuation of the follower by the chain projection 80 at that time will have no effect in actuating the valve 69.

FIG. 5 shows diagrammatically the pneumatic equipment and circuit employed in the apparatus. An intake tube 91 is connected to a source of compressed air and supplies the air to a T-piece 92 the side tube of which supplies a normally closed air valve 93 having an outlet 94. The valve 93 is shown in FIG. 1 at the front of the casing 27 and its outlet 94 is connected to the air pipe 81 shown in two places in FIG. 1. From the T-piece 92 an air pipe 95 runs to a T-piece 96 connected to the inlet 97 of an air control valve 98 and to an air pipe 99 which extends to the inlet air valve 69 previously described in connection with FIG. 4. The control valve 98 has alternative outlet ports 100 and 101 which are connected respectively by pipe 102 and 103 (which latter includes a flow regulator 104) to connections 105 and 106 at the opposite ends of air cylinder 54 shown also in FIG. 3. The valve 69 is normally closed by the spring of its valve stem 71 so that its outlet shown at 107 is disconnected from the air supply. The outlet 107 is connected by air pipe 108 to a T-piece 109 a side outlet 110 of which is connected to one end of control valve 98 to operate a movable plunger thereof while the end connection 111 of T- piece 109 is connected by a pipe 112 to an operating inlet connection 113 of valve 93.

During the functioning of the knitting machine prior to a parting off operation the air valves 69 and 93 remain closed and the plunger of control valve 98 is urged by a spring to a position in which the outlet 101 is in communication with the inlet 97. Air under pressure from intake tube 91 can thus only pervade the pipes 95 and 99 and, through the control valve 98, the pipes 103, so that the air cylinder 54 has its piston rod 55 withdrawn into the setting shown in FIG. 2 and the clamping bar66 and 67 are held open whilst the arm 44 supporting the funnel holds it in a position away from the pulling rollers 35 and 36. As soon as the chain projection 80 operates the follower 77 the air valve stem 71 is depressed to open the valve 69 thereby admitting air under pressure to the pipes 108, T-piece 109 and pipe 112. The air pressure then operates the plunger of control valve 98 to reverse its setting so as to admit air pressure through the pipe 102 to the inlet 105 of air cylinder 54 and open the pipe 103 to atmosphere. At the same time air under pressure flows through pipe 112 into inlet 113 of valve 93 to open the valve. This causes an air blast to be delivered through outlet 94 and through the pipe 81 causing air flow in tubes 32 and 33 and creating suction in delivery funnel 31.

The operation of air cylinder 54 operates the clamping means and pulling means so that the lowest complete article knitted in the tubular fabric 18 is parted from the remainder of the fabric and delivered into the funnel 31 from which it is drawn away along tubes 32 and 33. As soon as the projection 18 has passed the follower 77 the valve 69 is closed by its spring and by disconnecting the air supply from the pipe 108 causes the air valve 93 to be closed by an internal spring and the setting of the plunger of control valve 98 to be reversed by the spring acting thereon. T hereupon the air blast in pipe 81 ceases and connection 106 of air cylinder 54 is supplied with air while the connection 105 is opened to atmosphere. The parts operated by air cylinder 54 then return to the settings shown in FIGS. 2 and 3.

In the electrical circuit diagram shown in FIG. 6 the windings of motor 34 are indicated diagrammatically at 114. It will be seen that the motor is of three phase star wound type and it is energised from main leads L1, L2 and L3 there being a grounded neutral N. The leads L1, L2 and L3 are connected through an isolating switch 115 and normally open contacts C1, C2 and C3 of a contactor switch to the motor phase windings. The coil of the contactor switch is indicated at 116 and has one end connected through a fuse F to the neutral lead while its other end is connected via the contacts of a start button 117 to one of the main leads L3 on the motor side of the isolating switch 115. In parallel with the contacts of the start button 117 is a circuit which includes a normally open contact C of the contactor switch, the contacts of a centrifugal switch 118 which is incorporated in the motor 34 and the contacts of a stop button 119. The centrifugal switch 118 contacts are open when the motor is at rest or running below a required speed and closed when the motor is running at full speed. The motor 34 is normally kept running during the operation of the knitting machine, it being started by first closing the isolating switch 115 and then depressing the start button 117 and holding it depressed until the motor attains full speed. Closure of the start button 117 energised the coil 116 of the contactor switch the circuit of which coil is then maintained through contact C4 which will have closed, centrifugal switch 118 which will also have closed and the normally closed contacts of stop button 119. The motor will remain running until stopped either by a depression of stop button 119 or by a drop in speed of the motor 34 causing the contacts of centrifugal switch 118 to open.

The centrifugal switch 117 118 provides a safeguard against damage being caused if, due to unforseen circumstances, the pull on the tubular fabric exerted by the pulling rollers 35 and 36 should exceed a predetermined amount. The motor 34 is a relatively low powered motor which has just suflicient power for normal operation so that in the event of an excessive pull being applied to the tubular fabric by the rollers 35 and 36 the reaction through the rollers on the motor will cause its speed to fall suificiently to trip the centrifugal switch 118 so that its contacts will open and de-energise the contactor switch thereby switching off the motor.

It is also desirable to arrange that when the motor 34 driving the article separating apparatus is stopped, the operation of the knitting machine will also be stopped. To this end the contactor which i provided with additional contacts C5 and C6 which are normally closed and are connected to leads 120 and 121 which extend to an electric stop motion of the knitting machine. The contacts C5 and C6 are connected in circuit with a warning lamp 122 by further leads 123 and 124 and a grounded return. When the contactor switch is energised to close the main contacts C1, C2 and C3 the contacts C5 and C6 are opened and serve to break the stop motion circuit. As soon as the contact or switch is deenergised the contacts C5 and C6 close and complete the stop motion circuit thereby stopping the operation of the knitting machine and energising the warning lamp 122. The push buttons 117 and 119 are contained in the upper part of the right hand end of the casing 27 as seen in FIG. 1 as is also the warning lamp 122 which serves to illuminate a transparent cover 125. The contactor switch is mounted below the push buttons in the right hand end of the casing 27.

It will be understood that the apparatus provided by the invention is adapted for the performance of a method of producing knitted articles on a circular knitting machine by knitting the articles in succession connected to one another by a joining thread and subsequently separating them one by one from the connected series of articles by the procedure of applying a mechanical pull.to the lowermost article at appropriate intervals to rupture the joining thread. To this end the thread used for joining the articles together is weaker than the yarn used for forming the articles and is conveniently an alginate yarn as previously employed in connecting a succession of hosiery articles. The mechanical pull is applied by means of the cooperating rollers 35 and 36 into the nip between which the bottom part of the tubular string of knitted articles is introduced. Preferably the introduction between the pulling rollers is such that the tubular fabric is engaged with the rollers over only a part of its width. This tends to produce a greater degree of pull at one side than the other and thereby promotes the rupturing of the courses of weaker yarn serving to join the bottom article to the next one above it. The procedure is 8 such that the fabric on production is segregated from the pulling rollers except when a separating operation is required whereupon it is moved positively into engagement with the pulling rollers.

The timing of the actuation of the pulling means is such that it will occur at the same appropriate stage of a complete cycle of knitting operations since it is controlled by a projection on the chain 12. When the pulling means are actuated the clamping means comprising the clamping bars 66 and 67 operate to ensure that the pull is applied only to the lowermost one of the joints between articles connected end to end in the tubular fabric. The clamping means is so positioned that for various sizes of articles to be produced on the knitting machine one joint will always occur between the position of the clamping means and the position of the pulling means at the completion of each cycle of knitting operations.

It will be appreciated from the foregoing that the apparatus provided as illustrated in the drawings for separatin'gthe knitted articles one by one is particularly adapted for knitting as an attachment to an existing machine. This is facilitated by the fact that the apparatus consists mainly of the casing 27 fitted as a unitary structure with the pillar 28 and extension part 29, the delivery funnel 31 and pipes 32 and 33 being attached to the bottom of the casing 27, and the driving motor 34 being attached to the casing. In addition it is only necessary to provide the separately mounted control valve 69 and associated operating parts.

It will be evident to those skilled in the art that various changes of construction may be made in practising the invention. For example alternative protective arrangements are possible to safeguard against excess pull being adapted for fitting as an attachment to an existing matrifugal switch 118 there could be employed a thermal or current responsive overload switch in the circuit of the motor 34 to stop the motor on the occurrence of an overload. The pulling means and clamping means for acting on the tubular fabric may also take dilferent forms.

What I claim is:

1. Apparatus for use with a circular knitting machine for separating articles produced thereon in succession in continuous tubular form, comprising in combination supporting means adapted for mounting on the circular knitting machine below the needle cylinder thereof, means for gripping and pulling the tubular knitted fabric, means mounting the gripping and pulling means on the supporting means at a position to co-operate with the fabric delivered by take down rollers of the circular knitting machine, clamping means on said supporting means for clamping the tubular knitted fabric at a position sufiiciently higher than said gripping and pulling means to engage with the article next above that at the lower end of the tubular fabric and operative means for making the pulling means rapidly snatch the article at the end of the fabric when the clamping means is applied.

2. Apparatus according to claim i1 having the clamping means positioned to engage the tubular fabric immediately above the take down rollers of the circular knitting machine.

3. Apparatus according to claim 1 wherein said pulling means comprises two driven rollers serving to grip the knitted fabric between them when required and exert the downward pull thereon.

4. Apparatus according to claim 1 comprising guiding means presenting an aperture through which the tubular fabric is caused to pass on delivery from the take down rollers, means mounting said guiding means for movement to deflect the fabric into engagement with said pulling means, and means for moving said guiding means to deflect the fabric into engagement with said pulling means when an article is to be separated from the tubular fabric.

5. In a circular knitting machine, the provision of apparatus for separating knitted tubular articles produced in succession in continuous length by the machine, comprising supporting means positioned below the needle cylinder of the circular lmitting machine, gripping and pulling means carried by said supporting means so as to be engageable with and rapidly snatch the bottom end part of tubular fabric produced by the circular knitting machine, means whereby the lower part of the fabric produced is caused at intervals to engage said gripping and pulling means, clamping means operable to grip the tubular fabric at a position above said gripping and pulling means, and means for operating said clamping means periodically at times when the fabric is caused to engage said gripping and pulling means.

6. Apparatus as claimed in claim having said gripping and pulling means comprising a pair of rollers, means mounting said rollers to rotate in peripheral contact and means for driving said rollers to exert pulling action on said tubular fabric.

7. Apparatus as claimed in claim 6 wherein the rollers are displaced laterally from the normal path of the tubular fabric and wherein movable guiding means is provided to direct the fabric when required into engagement with the rollers by passing the fabric between the rollers from one end thereof.

8. Apparatus as claimed in claim 7 wherein said guiding mean-s is constituted by a control funnel.

9. Apparatus as claimed in claim 5 comprising operating means common to said pulling means and said clamping means for actuating them at required times.

Apparatus according to claim 9 having a device associated with said operating means to bring such means into action at appropriate times, said device being operable by a control member on the circular knitting, machine for actuation at an appropriate time during each complete cycle of knitting operations.

11. Apparatus according to claim 5 wherein said clamping means comprises opposed clamping bars between which, in their open setting the fabric is arranged to pass, two spaced rack bars respectively carrying said clamping bars with the latter projecting transversely from said rack bars into the space between them, means for mounting said rack bars to be slidable to move said clamping bars towards and away from one another and a rack Wheel engaging simultaneously with both rack bars at opposite parts of said wheel respectively for moving said rack bars to actuate said clamping bars.

12. Apparatus as claimed in claim 11 having guiding means for deflecting the fabric into engagement with said pulling means and a pivoted arm on which said guiding means is mounted for such movement and having a spindle to which said arm is secured for rocking said arm, said spindle having said rack wheel also secured to it.

13. Apparatus as claimed in claim 12 comprising a fluid pressure operated piston and cylinder device coupled to said spindle to effect rocking thereof to operate said guiding means and said clamping means.

14. The method of producing tubular knitted articles on a circular knitting machine consisting in knitting the articles in succession connected to one another by joining threads weaker than the yarn used for forming the articles, afterwards separating the articles from one another by clamping the articles and applying a mechanical pull at appropriate intervals to rupture the joining thread between the leading article in the succession and the article next thereto and moving the fabric bodily into engagement with mechanical pulling means whenever rupture of a joining thread is required.

References Cited by the Examiner UNITED STATES PATENTS 2,314,618 3/1943 Green 66-172 X 2,437,735 3/1948 Getaz 66-147 2,709,352 5/1955 Lawson 66--149 2,729,957 1/1956 Pope 66172 MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

P. C. PAW, Assistant Examiner. 

1. APPARATUS FOR USE WITH A CIRCULAR KNITTING MACHINE FOR SEPARATING ARTICLES PRODUCED THEREON IN SUCCESSION IN CONTINUOUS TUBULAR FORM, COMPRISING IN COMBINATION SUPPORTING MEANS ADAPTED FOR MOUNTING ON THE CIRCULAR KNITTING MACHINE BELOW THE NEEDLE CYLINDER THEREOF, MEANS FOR GRIPPING AND PULLING THE TUBULAR KNITTED FABRIC, MEANS MOUNTING THE GRIPPING AND PULLING MEANS ON THE SUPPORTING MEANS AT A POSITION TO CO-OPERATE WITH THE FABRIC DELIVERED BY TAKE DOWN ROLLERS OF THE CIRCULAR KNITTING MAGCHINE, CLAMPING MEANS ON SAID SUPPORTING MEANS FOR CLAMPING THE TUBULAR KNITTED FABRIC AT A POSITION SUFFICIENT LY HIGHER THAN SAID GRIPPING AND PULLING MEANS TO ENGAGE WITH THE ARTICLE NEXT ABOVE THAT AT THE LOWER END OF THE TUBULAR FABRIC AND OPERATIVE MEANS FOR MAKING THE PULLING MEANS RAPIDLY SNATCH THE ARTICLE AT THE END OF THE FABRIC WHEN THE CLAMPING MEANS IS APPLIED. 